120v motors plugged into 20a receptacles
- Thread starter fireryan
- Start date
Rick 0920
Senior Member
- Location
- Jacksonville, FL
- Occupation
- Electrical Instructor
See Table 210.21 (B)(3) Since it's a receptacle you have to stay within the listing. What would keep someone from unplugging the motor and using the receptacle for some other equipment?
If you don’t mind my asking what do these motors do?
They are up in a ceiling for air filtration motors so they will not be accessible from the floor
hbiss
EC, New York NEC: 2017
- Location
- Little Falls, New York NEC: 2017
- Occupation
- EC
not above the ceiling. Located on the ceiling
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Are thinking of oversizing because you are planning on having multiple fans on each circuit and are worried about the starting current?
I wouldn't. I would just look at the total FLA and let the breaker trip curve deal with it. So 20A / 2.6A = 7.69, so if you put 7 fans on each 20A circuit, the starting current, if they all come on at the same time, would be 35.7A or 179%. For a basic 20A breaker trip curve, you are looking a between 20 seconds and 250 seconds trip time (I used an Eaton BR trip curve). If your fans took more than 20 seconds to start, that's a bad fan design...
I wouldn't. I would just look at the total FLA and let the breaker trip curve deal with it. So 20A / 2.6A = 7.69, so if you put 7 fans on each 20A circuit, the starting current, if they all come on at the same time, would be 35.7A or 179%. For a basic 20A breaker trip curve, you are looking a between 20 seconds and 250 seconds trip time (I used an Eaton BR trip curve). If your fans took more than 20 seconds to start, that's a bad fan design...
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
What says you can't have receptacles above a ceiling?
hbiss
EC, New York NEC: 2017
- Location
- Little Falls, New York NEC: 2017
- Occupation
- EC
Years ago we were told one of the biggest issues with receptacles installed above drop ceiling was cords used most likely would produce toxic fumes during a fire. One funny inspector said he only allowed receptacles above drop ceilings wss for cell.phone chargers. Was a continuous fight with the people who made the connections for overhead projectors. I always installed a dup!ex receptacle in the drop ceiling facing down so power cord was not in an drop ceiling that was used for air return. ( air plenum ) . Never found out if any company manufacturers a little 1/10 HP or so sump pump with an approved cord & 120 volt male plug that is listed for inside of drop ceilings. One company had a dozen of them for HVAC units that they removed and cleaned several times a year.